Both linear and rotational hitters start with the meat of the bat higher than the back-shoulder. And since contact can be made below the belt, it is obvious the bat must be swung on a downward plane before it starts in an upward path. The main point of disagreement is where in the swing plane the bat bottoms out its trajectory. Many linear hitting coaches believe the bat should still be on its downward plane at contact.
Rotational hitting coaches instruct batters to keep their hands back and accelerate the bat-head on its downward path back behind the back-shoulder (back toward the catcher). The path of the bat plane will then bottom out about 18 inches from contact and be on a slight up swing in the contact zone. Below is a video that shows and discusses this swing plane.
Fastpitch Softball vs Baseball Swing Plane
Some linear fastpitch softball hitting coaches believe the upper cut in the rotational swing plane will not work for fastpitch softball hitting. To produce a linear swing plane, the batter is instructed to "swing down" to the ball. This instruction is based on the misguided belief that the swing plane must be on a downward path to create back-spin for maximum ball flight. Below we show video analysis of the most productive fastpitch hitters. The analysis shows their swing planes are angling upward at contact.
In our Instructional Video, The Final Arc 2, we explain that backspin is created when the bat strikes the lower-half of the ball, which is true regardless of whether the bat is angling upward or downward at contact.
Video Analysis Shows The Best Hitters "Swing Up" Not "Swing Down"
The video below features the swings of fastpitch softball hitters that hit home runs in the Women's College World Series. They not only hit with power, they also have some of the highest batting averages. Check out their swing planes.
Swing down to the ball may be a helpful batting tip for slap hitting where the objective is to use the batter's speed to beat out ground balls (i.e., for speedy left-handed batters to get a running start at contact). While these hitters perform a valuable service of getting on base, for most fastpitch hitters who want to drive the ball, the swing plane used by the hitters in the above video would be more productive.
Rotational Swing Plane Mechanics
Think of the plane of the swing as being a flat disc that is tilted down toward the plate so as to intersect the path of the ball in the contact zone. The bat, lead-arm and shoulders should all be in that plane from initiation to contact. The bat can be thought of as an extension of the lead arm. Keeping the lead-arm (including the elbow) in the plane of the swing is an absolute must.
That means the lead-elbow must always remain pointing into the plane of the swing. If the lead-elbow lowers (or drops) down out of the plane before contact -- the swing is basically ruined. The wrist will start to roll too soon and the bat-head will come out of the intended plane. This will normally cause inconsistent contact and usually results in weak grounders or pop-ups. Below is a video that shows a frontal view of the swing plane.